A department store maintains data on customers, products, and purchase records in three tables: CUSTOMER, PRODUCT, and PURCHASE. The store manager wants to know which product is on maximum discount for each category. Write a query to print the following fields for each category, ordered by category, ascending: category, product ID and discount for the product that has the maximum discount in the category. In the case of multiple products having same maximum discount within a category, print the product with minimum product_id.